The present invention relates to a vibratory conveying apparatus for material-handling applications, and more particularly to a vibratory conveying apparatus which comprises a piezoelectric driver for inducing a directional wave motion in an associated conveying bed.
Vibratory conveyors have found widespread use in many material handling applications. These devices typically include a conveying trough which is mounted for vibratory motion and a mechanical or electromagnetic driver which induces the vibratory motion in the conveying trough. In mechanically driven vibratory conveyors, the driver creates differing acceleration forces during its opposite strokes to thereby induce a directional motion to the material in the trough. In electromagnetically driven vibratory conveyors, the conveying trough is mounted for angular movement and the driver therefore creates a force vector which advances the material through the trough. U.S. Pat. Nos. 5,967,294 and 6,019,216, which are both hereby incorporated herein by reference, illustrate these types of vibratory conveyors.
Efforts have been made to develop vibratory conveyors which employ piezoelectric drivers. Piezoelectric drivers typically comprise a ceramic or other non-metallic material which, when electrically excited, vibrates at a frequency and amplitude commensurate with the electrical excitation. Generally speaking, these types of vibratory conveyors have been configured somewhat similarly to electromagnetically driven vibratory conveyors, that is, with the conveying trough mounted for angular movement so that the vibratory motion of the piezoelectric driver creates a force vector which acts to move the material in the desired direction. U.S. Pat. Nos. 5,472,079, 5,910,678 and 6,465,932, and Japanese Patent No. 62-218308, which are hereby incorporated herein by reference, illustrate vibratory conveyors which employ piezoelectric drivers.